Outlook pop-up warning

[kevmca]

Hi I would like to present a pop-up to users when they attempt to attach ANY document to an email AND the recipient for the email is not part of the senders trusted domains? Something like "You are sending an attachment to an untrusted recipient. Are you sure you want to proceed?"  Is this a valid use case for AIP? Or should we be using O365 DLP type capabilities?

[#2]

@kevmca 

@Enrique Saggese: Is this something you can speak to? 

[#3]

@kevmca 

We don't have that functionality natively, but it should be possible to do that via transport rules coupled tooltips (you can trigger transport rule on attachment size and putting an attachment size that is close to zero would catch any practical attachment).

Though I question if doing this might not cause some "warning fatigue" on the users and result in them getting desensitized and ignoring the warnings.